Patients who are brain dead will not survive. Brain death refers to the irreversible termination of whole brain function, including brainstem function. The respiratory center of the human body is located in the brainstem, and when brain death occurs in a patient, respiratory function stops and no medical treatment can be used to save the patient’s life. Therefore, the international criteria for determining brain death include irreversible deep separation, absence of voluntary breathing, disappearance of brainstem reflexes, and disappearance of all electrical brain activity. After these four judgments, repeat tests within 24-72 hours are needed to determine again, and if there is no change, the patient can be declared to have entered death.